4-N-batyroxymethyl-1,3-dioxolanes

ABSTRACT

The present invention relates to novel flavourings, in particular certain dioxolane derivatives and a process for the manufacture thereof, to flavouring compositions containing said derivatives and with a method of imparting a flavour to materials by means of said derivatives.

United States Patent n Lamparsky I 5 4 I 4-N-BUTYROXYMETHYL-1,3-DIOXOLANES [75] Inventor: Dietmar Lamparsky,

Wangen-Dubendorf, Switzerland [73] Assignee: Givaudan Corporation. Clifton NJ.

[22] Filed: July 12, I972 [2]] Appl. No.: 270,879

[30] Foreign Application Priority Data July 23. [971 Switzerland lO893/7I [S2] U.S. CI. 260/340.9; 426/221; 426/222 [SI] Int. Cl C07d 13/04 [58] Field of Search 260/3409 [56] References Cited UNITED STATES PATENTS 1680.735 6/1954 Fegley ct al. 260/3409 X 1 May 13, 1975 OTHER PUBLICATIONS Chemische Werke Huels Chem. Abs volt 70:372I3t (1969), Abs. of Fr. Pat. No. 1502385,

Fang 0 0 4 260/3409 X Nordstrom 0. 260/340,) X

Primary Examiner-Joseph A. Narcuvage Almrney, Agent. or Firm-Thomas Cifelli. Jr.

[57] ABSTRACT 4 Claims, No Drawings 1 4-N-BUTYROXYMET HYL- l ,S-DIOXOLANES FIELD OF THE INVENTION This invention relates to the fields of flavourants and substituted dioxolanes.

DESCRIPTION OF THE PRIOR ART British Patents Nos. 1,195,909; 1,166,636 and 559,451 are the closest prior art known to the inventor; but none of these patents discloses compounds having the striking flavour and properties of the compounds of this invention.

SUMMARY OF THE INVENTION The dioxolane flavourants provided by the present invention have the following general formula 2 3 \c R1 co CHg-EQH wherein R represents a straight-chain or branchedchain alkyl or alkenyl group containing 2-6 C-atoms, R represents a hydrogen atom or an alkyl group containing l3 C-atoms and R" represents a grouping of the formula in which R represents a hydrogen atom or a hydroxy group and R and R each independently represent a hydrogen atom or a straight-chain or branched-chain alkyl or alkenyl group containing up to 6 C-atoms.

According to the process provided by the present invention, the dioxolane derivatives of formula 1 above are manufactured by either a. cyclising a diol of the general formula RCOOCH --CHOHCH OH with a carbonyl compound of the general formula R COR (III) b. esterifying the primary alcohol group of a compound of the general formula with an acid of the general formula or a functional derivative thereof; in which formulae R, R and R have the significance given earlier.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As aforementioned. in the general formula I of the novel flavourants of this invention:

R represents a straight-chain or branched-chain alkyl or alkenyl group containing 26 C-atoms. Examples of such groups are: ethyl, n-propyl, isopropyl, nbutyl, isobutyl, secbutyl, tertbutyl, n-pentyl and n-hexyl (including their structural isomers), and l'-propenyl, l'-methyl-l' propenyl and 2'-propenyl, R preferably represents the n-propyl group, in which case the derivatives of formula I are butyric acid esters.

R represents a hydrogen atom or an alkyl group containing l-3 C-atoms, ie the methyl, ethyl, n-propyl or isopropyl group. In the preferred derivatives of formula I, R represents a hydrogen atom or the methyl group.

R represents a grouping of formula (a) or (b). Examples of alkyl and alkenyl groups which may be present on said groupings as a substituent denoted by R and/or R are alkyl groups containing l-6 C-atoms such as those mentioned earlier in connection with R and R and alkenyl groups containing 2-6 C atoms such as vinyl, l'-and 2'-propenyl, l'-butenyl etc. In the pre ferred derivatives of formula I, R represents the lpropenyl group (CH=CH-CH or the 1' hydroxyethyl group (CHOHCH The dioxolane derivatives of formula I provided by the present invention are distinguished. as has surprisingly been found by particular flavour properties, on the basis of which they can be used as flavourings in aroma compositions. Of particular interest is the but tery aroma of certain of the derivatives of formula I, particularly of the following three derivatives:

2-( l '-propenyl)-4-n-butyroxymethyl-dioxolane [for mula I: -CH CH CH R H, R CH=CHCH 2-methyl-2-( l '-hydroxyethyl )-4-n-butyroxymethyldioxolane [formula I: R CH CH CH R H, R =CH=CHCH 2-(2'-methyl-propyl)-4-n-butyroxymethyl-dioxolane [formula I: R CH CH CH R H, R CH The latter derivative also displays an interesting cocoa-like aroma. Other derivatives of formula I have interesting fruity aroma notes and can therefore be employed as components of fruit aromas, for example of strawberry type aromas,

The concentration of the dioxolane derivatives of formula I in aroma compositions such as butter or fruit aromas can lie between about 0.01 and parts per thousand, but it preferably lies in the range of 0.1 to 10 parts per thousand, In finished products aromatized with such aroma compositions such as pastry, fruit tarts etc correspondingly lower concentrations of the dioxolane derivatives of formula I (for example 01 to 10 parts per million) are present.

The following Examples illustrate aroma compositions containing a dioxolane derivative of formula I.

EX AMPLE I weight butyroxymethyl-dioxolane is added to an aroma composition A consisting of:

diacetyl 51 parts by zvelght butyric acid lactic acid vanillm 4 butyric acid ethyl ester l heliotrupin 5 benzaldchyde parts by weight EXAMPLE ll l parts of 2-methyl 2-l l'-hydroxyethyl l-4-nbutyroxy-methyl-dioxolane are added to the butter aroma composition A set forth in Example l. The composition C thus obtained is used for aromatizing pastry in a dosage of 0.5 2. The pastry aromatized with composition C is unequi\ ocally superior from the point of view of flavour to that aromatized with 0.5? ofcomposition A.

In embodiment la) of the process. an aldehyde or ketone of formula lll is acetalized or ketalised in a manner known per se with a diol of formula ll. namely an a-monoester of gly'cerine. with cyclisation to a dioxolane derivative of formula i. As usual. the acetalisation or ketalisation is advantageously carried out by heating the mixture of the components in the presence of a sol- \ent and expediently in the presence of an acidic catalyst with continuous removal of the water w hich forms. for example. by means of an entraining agent.

As the entraining agent there can be used solvents which are usually employed for this purpose such as. for example. aromatic and saturated aliphatic hydrocarbons teg. benzene. toluene or n-pentane l. Such solvents facilitate the continuous removal of the watertwhich forms during the cyclisation iby' azeotropic distillation.

As acidic catalysts there can be used the substances which are usually used for acetalisations or ketalisations; for example. mineral acids such as sulphuric acid. phosphoric acid and perchloric acid. strong organic acids such as trichloroacetic acid or p-toluenesul phonic acid and Lewis acids such as. for example. boron trifluoride etc.

In embodiment (bl of the process. the primary alcohol group ofa cycloacetal or cycloketal alcohol of formula l\' is esterified to yield a dioxolane derivative of formula I with an acid offormula or with a functional derbative of such an acid teg. the anhydride or a halide such as the chloride). The esterification can be carried out according to methods known per se; for example. by acylation according to Schotten-Baumann in the presence of a base. or by reaction of an alcohol of formuia l\' with an acid of formula or its anhydride in the presence of an acidic catalyst and expediently in the presence of a solvent and with continuous removal of the water which forms. As acidic catalysts there can be used those mentioned earlier in connection with embodirnent (al of the process.

The starting materials of formula ll. ill. I\ and can. insofar as they are not known. be prepared according to methods known per se.

1.4-Diand 1.2.4-trisubstituted dioxolane derivatives such as those of formula I hereinbefore can theoreti' cally exist in a cis and a trans form (see. for example. J. Chem. Soc. 19 0. 263 J. It will be undertood that formula l is meant to include the cis and trans forms as well as mixtures of these two forms. The derivatives of formula I manufactured in accordance with the process provided by this invention are obtained mostly as cistrans isomer mixtures with about the same amounts of cis and trans forms.

The following Examples illustrate the process provided by the present invention.

EXAMPLE 1 48.6 g of glycerin-a-monon-buty'rate. 14.4 g of nbutyraldehyde and 150 ml of hexane are boiled in the presence of 0.1 g of p-toluenesulphonic acid for 14 hours under a w ater-separator. The mixture obtained after expulsion of the theoretically expected amount of water is cooled and carefully washed neutral. After drying 0\ er potassium carbonate. the solvent is distilled off and the residue 141 g) fractionally distilled. The propyl-4 butyroxymethyl-dioxolane which is obtained in a yield of 8 boils at C 0.2 mmHg'. m?" [4315.

EXAMPLE I 300 g of glycerin-a-mono-n-butyrate and g of crotonaldehyde are dissolved in 1200 ml of benzene and boiled in the presence of 4 g of p-toluenesulphonic acid under a water-separator. After cooling the mixture. it is transferred into a separating funnel and washed neutral with water. 5? sodium hydrogen carbonate solution and water. The solvent is subsequently distilled off and the residue fractionally' distilled on a packed column. The Z-t l propenyll-4-nbuty'roxymethyl-dioxolane which is obtained in a yield of 75 Q boils at ltll-lO2C 0.4 4 mmHg; n

EXANlPLE 3 200 g of acetylmethylcarbinol. 366 g of a-glycerin-nmonobuty'rate. 1300 ml of benzene and S g of p-toluenesulphonic acid are mixed in a 4'necked stirring flask provided with a water separator and boiled at reflux with stirring. After 5 hours. the amount of water expelled amounts to about 40 ml. corresponding to an approximately complete reaction. The mixture is cooled and poured into 500 ml of saturated aqueous sodium hydrogen carbonate solution. The benzene solution is separated off in a separating funnel and washed thoroughly with water. After drying for a short time. the benzene is distilled off and the residue fractionated on a packed column. There are thus obtained 18: g of Z-methyLLt l '-hy'droxyethyll-4-nbutyroxymethyl-dioxolane of boiling point l04-lUoC 0.1 mmHg inf 1.448 in the form of a mixture of I stereoisomers in the ratio of ca l:l.

EXAMPLE 4 chloride are then added dropwise over a period of minutes and the resulting mixture is stirred for a period of 5 hours. the temperature being allowed to rise gradually to room temperature. The mixture is then washed and formula ofthis material (see Example I l ofTableJ, as well as those of other dioxolane derivatives encompassed by this invention, are given in the accompanying Table:

What is claimed is:

l. A compound selected from the group consisting of 2-( l '-propenyl)-4-n-butyroxymethyl-dioxolane; 2- methyl-2-(l '-hydroxyethyll-4-n-butyroxymethyldioxolane and 2-( 2 '-methyl-propyl )-4-nbutyroxymethyl-dioxolane.

2. 2-( l '-Propenyl) 4-n-butyroxymethyl-dioxolane.

3. 2-Methyl-2-( l'hydroxyethyl l-4-n-butyroxymethyldioxolane.

4. dioxolane.

2-( 2 -Methyl-propyl )-4-n-butyroxymeth yl- 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 2-(1''PROPENYL)-4-N-BUTYROXYMETHYL-DIOXOLANE, 2-METHYL-2-(1''HYDROXYETHYL)-4-N-BUTYROXYMETHYL-DIOXOLANE AND 2-(2''METHYL-PROPYL)-4-N-BUTYROXYMETHYL-DIOXOLANE.
 2. 2-(1''-Propenyl)-4-n-butyroxymethyl-dioxolane.
 3. 2-Methyl-2-(1''hydroxyethyl)-4-n-butyroxymethyl-dioxolane.
 4. 2-(2''-Methyl-propyl)-4-n-butyroxymethyl-dioxolane. 